New cycloartane type-triterpenoids from the areal parts of Caragana sukiensis and their biological activities.

A comprehensive re-investigation of aerial parts of Caragana sukiensis resulted in the isolation of twelve compounds (1-12) including three new cycloartane type triterpenoids (3-5) respectively. Chemical structures of the isolated compounds were established by analysis of their IR, HRMSESI, 1D and 2D NMR spectroscopic data. In addition, these compounds were evaluated for their cytotoxic activity against cancer lines (HeLa, A549, MCF-7, DU-145) and Human embryonic kidney cell line (HEK-293). The results indicated that compound 8 showed potent cytotoxic activity against A549 with IC50 value of 1.54 μM which is comparable to standard drug, doxorubicin. Further, flow cytometric analysis showed that compound 8 arrested the cell cycle in the Go/G1 phase leading to apoptotic cell death. In addition, Hoechst 33258 staining, Annexin V-FITC assay and measurement of mitochondrial membrane potential also suggested that 8 induced cell death by apoptosis. Further, all the isolates were also screened for their antifeedant and insecticidal activity against tobacco caterpillar (Spodoptera litura), using no-choice leaf disk method. Among screened compounds 1, 3, 4, and 6 showed potent antifeedancy with ED50 values of 0.59, 1.19, 0.67, and 1.68 μg/cm2. Overall, this study identified a novel class of cycloartane tritepenoids as potent cyotoxic agents as well as antifeedants.